chromium/third_party/blink/web_tests/inspector-protocol/resources/indexeddb.html

<!DOCTYPE html>
<html>
  <head>
    <script>
window.dbPromise = new Promise(resolve => {
    var dbRequest = indexedDB.open('testDatabase1', 2147483649);
    dbRequest.onsuccess = () => resolve(dbRequest.result);
});
    </script>
  </head>
</html>